The invention relates to a telephone handset suitably a radio telephone handset.
There is a general drive in the field of mobile telephony to produce more compact telephone arrangements particularly for ease of transportation. There is, however, a conflicting, mainly psychological, requirement for a telephone to bridge the gap between the users ear and mouth to approximate the feel of using a radio handset to that of a traditional landline telephone.
One of the ways in which this has been achieved is by providing a hinged flap attached to the main body of the telephone that is pivoted to a position in which it overlaps the main body when stowed but extends the overall length of the phone when in use. One example of such a phone is found in U.S. Pat. No. 4,845,772.
Such phones do, however, tend to be relatively filmsy and prone to damage especially when the flap is open since it is then extremely prone to accidental knocks or other rough treatment. The hinged flap also presents the difficulty of implementing a reliable conductive path from the microphone to the main body of the telephone across the hinge.
Another arrangement that overcomes some of the disadvantages inherent with a hinged flap is described in EP 0 414 365. The compact telephone or handset described in this patent comprises a main body and a cover portion arranged for longitudinal sliding movement relative to the main body. In the retracted position the phone is compact and easy to store. In the extended position the phone is dimensioned such that it comfortably bridges the gap between the user""s ear and mouth. The design can be made both compact and relatively robust.
In the handset described in EP 0 414 365 the connection enabling the call answer/send mode is only made when the cover portion is in its fully extended position. Hence the handset can only be used for making or answering a call when the cover is in its fully extended position.
In accordance with a first aspect of the present invention there is provided a radio handset comprising a housing having a key pad including a plurality of keys mounted on a main body and an extending portion mounted for longitudinal slidable movement between a first position in which the plurality of keys are concealed and a second position in which the plurality of keys are exposed, and a processor operable to perform respective predetermined functions responsive to respective sequences of actuations of the keys, the processor means being operable to perform the predetermined functions corresponding to the respective sequences of actuations of exposed ones of the keys for a range of positions of the extending portion.
A sequence for the purposes of this specification comprises a single actuation. In prior arts handsets of the type described in the introductory portion above the handsets are able to perform certain functions, such as making or receiving a call, only when the cover portion is in the fully open position. Making and receiving calls is impossible when the cover is in a position other than the fully open position. This means that the phone needs to be properly open before a call can be placed or received. If the sleeve portion does not xe2x80x98lockxe2x80x99 in the correct position, then the performance of the handset is impaired.
The present invention enables the processor to perform predetermined functions in response to respective sequences of exposed ones of the keys for a range of positions of the extending portion. The problems associated with specific functionalities corresponding to specific positions of the extending portion are, therefore, ameliorated.
Preferably, at least one key in addition to the plurality of keys is exposed when the extending portion is in the first position. This key may be operable to control the volume of the output of the radio handset. If an incoming call is indicated, actuation of an exposed key preferably places the handset in the off-hook condition. This enables a call to be answered.
The processor means is preferably operable to perform the predetermined functions corresponding to sequences of actuations of the exposed ones of the keys for each position of the extending portion. By allowing exposed keys to be used to control operation of the microprocessor at each position of the extending portion, there is no difficulty in ensuring that the extending portion is properly positioned at a particular location before a particular function can be performed. Provided the relevent keys are exposed, a function can be performed. This ensures that operation of the handset is simplified. The extending portion can preferably occupy any position intermediate the first and second positions.
The main body preferably comprises a first transducer and the extending portion a second transducer, the first and second transducers being operational when the extending portion is in the first and second positions and positions intermediate the first and second positions. The first transducer is typically a speaker or ear piece and the second transducer a microphone.
Movement of the extending portion from the first position preferably causes a call to be answered. Movement of the extending portion to the first position preferably causes a call to be terminated. This provides the user with options other than actuation of keys for answering and terminating calls.
In accordance with a second aspect of the present invention there is provided a radio handset comprising a housing having a key pad including a plurality of keys mounted on a main body and an extending portion mounted for longitudinal slideable movement between a first position in which the plurality of keys are concealed and a second position in which the plurality of keys are exposed, and processing means operable to place the handset in an off-hook condition with the extending portion in the first position, the second position and at least one intermediate position.
By enabling the handset to be placed in the off-hook condition in the first and second positions and at least one intermediate position, answering a call is not unduly restricted by the position of the extending portion. This again simplifies operation of the handset.
In accordance with a third aspect of the present invention there is provided a portable telephone comprising a set of keys; a cover portion movable between a first position covering the set of keys and a second position not covering the set of keys; and a further key not covered by the cover portion in either position, which has a first function when the cover is in the first position and a second function when the cover is in the second position.